Air-cushion.



'No. 787,473. PATENTED APR. 18; 1905; G. R. SGHWALENBERG. AIR. CUSHION.

APPLICATION FILED NOV. 30,1903.

UNITED STATES Patented April 18, 1905.

PATENT OFFICE.

AIR-CUSHION.

SPECIFICATION forming part of Letters Patent No. 787,473, dated April 18, 1905.

Application filed November 30, 1903. Serial No. 183,258.

To aZZ whom it may concern.-

Be it known that I, CARL REINHOLD SCHWALENBERG, a subject of the Grand Duke of Baden, and a resident of 14 Heidelbergerstrasse, Mannheim, in Grand Duchy of Baden, German Empire, have inventedcertain new and useful Improvements in Air-Cushions, of

which the following is an exact specification.

My invention relates to improvements in air-cushions manufactured of elastic indiarubber plates, and has for its purpose to provide means for avoiding that the plates lose their elasticity and form as well as their strength.

In order to make my invention more clear, I refer to the accompanying drawings, in which Figure l is partly a plan and partly a section on line A B of Fig. 2 of 'an air-cushion constructed according to. my invention. Fig. 2 is a section of the same on line C D of Fig. 1.

In the drawings, a. is aring-formed indiarubber air-cushion. Y

Z) represents wedge-formed pieces of'tricot fixed to the walls of the cushion. It will be understood that the Wedge shaped tricotpieces may be fixed to the inside as well as to the outside of the cushion. The purpose of this construction is the following: The'walls near the inner circumference or cut-out of the air-cushion will soon get-loose and baggy by the pressure exerted from outside by the person using the cushion. The cushion there-. fore becomes thinner as its surface around the cut-out has increased. As the inner pressure has the same amount per square inch all over the inner surface of, the cushion, the specific tension upon the part around the'cut-out of 'to the figures. v

It'is well. known'that trlcot can only be.

stretched in one direction. If one continuous piece of tricot would be cemented all around the inner circumference of the cushion, so

that it can only stretch in the cross direction,

the cushion would'lose its elasticity in'the longitudinaldirection of the strip. In order tially as described and to do away with this disadvantage, wedgeshaped pieces of tricot are provided accord- 'ing to the present invention, which wedgeshaped pieces are out so as to allow a stretching in the. cross direction, the stretching in the longltudlnal direction being allowed on It will also-be understood that the whole my invention, what I desire to secure by Letv ters Patent of the United States is 1. In an elastic air-cushion, the combination of a ring-shaped india-rubber cushion with wedge-shaped pieces of tricot fixed' to the wall of the cushion at the inside of the ring, each of these tricot piecesallowing independently from the other pieces, a limited stretching of that cushion part to which it is cemented, substantially as described and for the purpose set forth.

with a wedge-shaped piece of tricot, fixed'to the inside of the wall of the cushion at the inside'of the ring, the wedge-shaped tricot pieces partly permitting a stretching of their proper cushion-parts in substantially radial direction, partly allowing a stretching in substantiallycircumferential direction, substanforjthe purpose set forth. i y In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

I CARI: REINHOLD SCH\\' .-\LE.\'BERG.

W'Vitnesses:

' JACOB ADRIAN, H. W. HARRIS. 

